As fastening tool using a pop rivet, there has been proposed and utilized a manual riveting tool wherein a fastening shank of the pop rivet is inserted into a nose piece 10 of the tool, as shown in FIG. 1, and is grasped with a pair of jaws while a head portion of the rivet is abutted against the margins of a hole of one element to be fastened and then levers 12, 12 of the tool are closed toward each other to allow an associated ratchet mechanism to operate the jaws for tearing off the protruding shank portion forcibly, or a pneumatic riveting tool wherein a fastening shank of the pop rivet is grasped by a pair of jaws which are pulled by compressed air introduced into a cylinder tube 14, as shown in FIG. 2.
However, the manual riveting tool has a disadvantage in that the stroke length for tearing off the shank is so short that the levers must be repeatedly operated for fastening a single rivet, resulting in troublesome and fatiguing operation. On the other hand, the pneumatic riveting tool has a disadvantage in that a compressor and air tubing are required for feeding the compressed air, leading to an inconvenient and large tool.
Thus, a general object of the invention is to provide a riveting motor tool which is portable and convenient in the fastening operation.